Alternating-current relay



M. L. ALMQUIST ALTERNATING CURRENT RELAY June 5, 1928.

Filed March 1926 l J 4 I R, 0 Z

11 4% AA. 1 W? v I I L Elk: 1 :3 J 1 i C i l 02- n l I mm i2 INVENTOR l rent of, for example, cycles, for transmisdifferent embodiment of the mv Patented June 5,1928. g V 1,672,049

UNITED STATES I PATENT, OFFICE;

MILTON L. ALMQUIST, OFBROOKL YN, NEW YQRK, 'ASSIGNOR TO. AMERICAN TELE- PHONE AND TELEGRAPH COMPANY, CORPORATION OF NEW YORK. I

ALTEBNATING-CURRENT RELAY. Application filed Mal-ch29, 1926. Serial No. 98,403.

This invention relates to electromagnetic I While the nature of the invention will be relays, and particularly to arrangements for pointed out with particularit i th operating a direct current relay from the pended claims, the invention itself both as to contacts of an alternating current relay. its objects and features will be better under- 5 Alternating currents are generally emstood from the detailed description hereinployed for the transmission of signalsc At after following when read in connection the transmitting end of a signaling system a. with the accompanying-drawing in which igh frequency current of, for example, 1,000 Figure 1 represents one embodiment of the cycles, is modulated by a low frequency curinvention, and Fig. 2 represents a slightly ention. Simsion to a distant station. Atthe'distant stailar parts will be designated by similar reftion a demodulator is provided for demoduerence characters wherever they appear lating the low frequency current of 20-cycles throughout the drawing. With the underfrom the high frequency current of 1,000 standing that the invention will be defined 15 cycles. 'A polar relay is provided at the dis- 1n the appended claims, the following detant station which is arranged so that its scription is given.

armature vibrates,at the frequency of the Apolar or alternating current relay is desdetected signaling current. It is also necignated by'the reference character W havessary in such a system to provide circuit ing an armature A and contacts 1 and 2 arrangements for continuously operating a which are associated therewith, the armature second relay from the contacts of the polar A, resting against either of these contacts.

relay whenever the polar relay is energized When alternating current of the signaling 7 by the low frequency signaling current. frequency is applied to-leads L, the arma- This second relay may be employed for reture A will vibrate between the contacts 1 5 cording the signal. g and 2 at the frequency of the current ap- In former arrangements the polar relay plied. A direct current relay is designated was. associated with a condenser, an alterby the "reference character W and has an nating current relay, and a battery so that armature A associated therewith which the polar relay alternately charged and dismoves between contacts 3 and 4. Whenthe charged the condenser through the winding armature A closes contact 3, a'circuit L a of the alternatingcurrent relay, thecharge connected between contact 3 and the armaanddischarge current of the condenser conture A is operated. Two condensers, C, tinuously operating the alternating current and C are provided in this system, and a relay. However, in those arrangements the battery B is employed for charging these armature of the polar relay had to close each condensers. There are two resistances R, contact for an appreciable period of time in and R, included in the system, the resistance order that the charge and discharge curbeing employed for controlling the dis- 9o rent of the condenser might be suflicient to charge of the condenser C and the resistance keep the alternating current relay continu- R for controlling the rate of charge of these 40 ously operated. condensers, as will be understood from the It is. an object of this. invention to prodescription hereinafter following. 5 Vide arrangements for interconnecting a When the armature A of the relay l/V, vipolar-relay, or any relay the armature of brates with suflicient amplitude, itwill alterwhich vibrates at the frequency of the alternately make contacts land 2. When contact.

' 45 nating current, or at a multiple of the fre- 1 is made by the armature A,, the condensers quency, when alternating current is applied C and 0 will be charged from the batter thereto, and a direct current relay so that B, the circuit including the battery B, the

the direct current relay may be continuously resistance R,, condense-r Q condenser G, operated from the contacts of the alternating and the armature A,. Resistance R being 45 current relay, the operation of the direct in series in this circuit, prevents sparking current relay not being dependent upon the at the contact 1, which might be caused by I length of time that the armature of the al-' thecharge of the condensers at too high a ternating current relay closes each contact. rate. Condenser C bemgm shunt with the winding of the relay 7 W discharges through this relay causing it to remain operated until the armature A, travels from contact 1 to contact 2 and back again to 5 contact 1.

contact 1, charging up condensers C and C 7 and so it continues. The condenser C, is of a sufiiciently high capacity to keep relay "W operated 'for at least the time require armature A, to travel back and forth between contacts l and 2. Also relay W will remain operated as long as the armature A, 90 continues to move between contacts 1 and 2 in response to the flow of alternating current through the winding of the relay 'By having the condensers C, and C of the propercapacities and by employing a wind- 2 ing for the relay W of the proper impedance, it is possible to definitely limit the lowest frequency at which the vibration of the armature A, will cause continuous operation of the relay W The upper limit of the trequency at which the system will operate is determined largely by the maximum frequency at which relay W, will respond. Obviously, if current of a frequency greater than the upper limit is applied to the winding of the reIayW the armature A, of that relay will not be responsive. It the energy level which can be supplied to the winding of the relay W' is limited by the use of a current limiting device w of any type .well known in the art, the limits of frequency atwhich the system will be responsive may be kept close together, thus rendering the system quite'selective with respect to the frequency range. Thecurrent that flows throu h the winding of the relay W is practical y independent of the intensity .with which the] relay W is operated.

The currentthat of the relay W is also inde endent of the time that the armature A, o the relay W rests against either contact. Thus, the relay is kept continuously operated as long as the armature A, of the relay W, vibrates with suficient amplitude to strike both contacts 1 and 2.

' Fig. 2 shows a,.modification ofthe arrangements disclosed in Fig. l in which the elements are similar to those in Fig. 1 with the exception that'a retardation coil R is included in place of the resistance in Fig. 1. However, in this embodiment of the invention the time necessary for the armature to rest against contact 1 is increased in order to continuously operate the relay have been assowithout departing dbythe.

ternating current, a

densers from the battery on closure of ture resistance,

flows through the winding.

arrangements relay from the contacts of the polarlzed alrent' relay, two condensers,

" ne raoea ciated with Fig. 1, the preferred embodiment of the invention, it is to be distinctly understood that by slight modifications of'the invention well known to those skilled in the art one resistance may be employed in place of these two resistances.

While the arrangements of this invention have been shown and described-in two particular embodiments, it is to .be understood that the invention is capable of embodiment in other and widely varied organizations from the spirit of the invention and the scope of the appended claims.

What is claimed is v *1. In combination, an alternating current polarized relay connected to a source of aldirect currentrelay, a battery, two condensers, and a resistance, one condenser being in shunt with the winding of the direct current relay, the armature ofthe alternating current polarized relay causing the charge of the. two conone contact thereof, the resistance regulating the rate of charge of the condensers, the arma 1 or the alternating current rela causing the discharge of the second con enser on closure of the other contact thereof.

2. .A system 'for continuously operating a direct current relay from the armature of an alternating current relay when current of predetermined frequency flows through the winding of the alternating current relay, comprisingtwo condensers, abattery, and a said condensers being charged by the battery through the resistance. on closure of one of the contacts associated with the armature ofthealternating currernt relay, one of said condensers being connected to the winding of the direct current relay and being discharged to operate the direct current relay on closure of the other of the contacts associated with the armature of the alternating'current relay.

3. In combination, a polarized alternating current'relay having a normally open 1contact gap, a battery, a direct current retwo condensers, a resistance, and circuit to operate the direct current tern'ating current relay by the charging current of the battery and by the discharging current of one of the condensers connected to the winding of the direct current relay,

the battery being employed for charging the condensers, the res; tance being sufficiently large to control the rate of charge of the condensers.

ft. In combination, a polarized alternat- '1 ing current relay having a normally open armature contact gap, a battery, a direct curtwo resistances, and circuit arrangements to operate the direct current relay from the armature conf- 3 tacts of the polarized alternating current relay, the condensers being charged by the battery through one resistance when the armature of the polarized alternating current relay engages one contact, the condensers being discharged when the armature'of the polarized alternating current relay engages the other contact, one condenser be ing in parallel relationship with the direct current relay and being of a sufliciently high capacity to keep the direct current relay operatedduring the time necessary for the armature of thepolarized alternating cur-- rent relay to'move back and forth between its contacts, the other condenser being dis-' charged through the other resistance when the armature of the polarized alternating current relay is on the other contact.

5. In combination, an alternating current relay having an armature which moves between its contacts when current of a frequency between predetermined limits flows through the winding thereof, a direct current relay, two condensers,'a batter and a resistance, said direct current relay ing in parallel relationship with one condenser which is of suflicient capacity to hold said direct current relay operated during the time required for the armature in the alternating current relayto move back and forth between its contacts, said condensers being charged by the battery through the resistance on closure of one contact of the alternating current relay.

6. A system for operating a direct current relay from the contacts of a vibrating contact polar relay, comprising two condensers, the direct current relay being operated by the discharge of one condenser when the armature of the polar relay closes one of its contacts, a resistance, the other condenser being discharged through the resistance when the armature of the polar relay closes the same contact, and a battery, the condensers being charged by the battery when the armature of the alternating current relay closes the other contact.

7. A system for operating a direct current relay from the contacts of a vibrating contact polar relay, comprising two condensers, a resistance, and a battery, the condensers being charged by the battery when the armature of the polar relay closes one. of its contacts, one condenser being discharged through the direct current relay to keep it operated and the other condenser being discharged through the resistance when the armature of the polar relay closes the other of its contacts, the capacity of the condenser discharging into the direct current relay being sufliciently large to keep it operated for at least one complete movement of the arma ture of the polar relay between its contacts.

In testimony whereof, I have signed my name to this specification this 24th day. of March-1926. 4

. MILTON L. ALMQUIST. 

